Re: [G++ n00b] getche() in G++ ?

[Lionel B]

On Thu, 01 Nov 2007 19:52:26 -0700, Paul Pluzhnikov wrote:

> Stefan Kristensen <stefan@jems.dk> writes:
>
>> My old school book has an example that uses getche(), which I
>> understand is not C++ standard and is not supported by G++. Can anyone
>> help me out and tell me what to use instead?
> 
> getchar() is close, but not exactly equivalent. Reading keyboard
> *immediately* (without waiting for carriage return) is rather tricky on
> UNIX.

Indeed it is... I wrote this routine some time ago (works on Linux, not 
sure about FreeBSD). It uses "termios" routines to put stdin 
(temporarily) in "raw" mode:

#include <termios.h>

inline int getche()
{
        termios settings;
        const int fd = fileno(stdin);
        if(tcgetattr(fd,&settings)<0) {
                std::cerr << "error in tcgetattr\n";
                return 0;
        }
        settings.c_lflag &= ~ICANON; // into "raw" mode
        if (tcsetattr(fd,TCSANOW,&settings)<0) {
                std::cerr << "error in tcsetattr\n";
                return 0;
        }
        int c = getchar();
        settings.c_lflag |= ICANON; // back to "canonical" mode
        if (tcsetattr(fd,TCSANOW,&settings)<0) {
                std::cerr << "error in tcsetattr\n";
                return 0;
        }
        return c;
}

I'm sure it's not perfect, but it does the job for me...

Regards,

-- 
Lionel B